A first report that milk contains a substance capable of reducing cholesterol blood levels appeared in 1974. Mann, G. V. and A. Spoerry, Studies of Cholesteremia in the Maasai, American Journal Clinical Nutrition, 27, 464 (1974). This report was based on a feeding trial with Maasai male adults in Kenya. The objective of the test was to determine the effect on cholesterol levels of the addition to Maasai milk of an emulcent food additive (Tween) which had been shown to cause a cholesterol rise in rabbits. No significant effect was found from the food additive, but analysis of the data showed that the more milk consumed the lower the level of cholesteremia observed in the men. Subsequent feeding trials which were conducted with milk and yogurt by Dr. George V. Mann and his associates, using rats, rabbits, and human subjects, confirming the observation that milk contains a substance which lowers the level of cholesterol. As named by Dr. Mann, this substance is now called Milk Factor or MF. See Nair, C. R. and G. V. Mann, Atherosclerosis, 26, 335 (1977); and Mann G. V., Atherosclerosis, 26, 335 (1977); and Mann, G. V., Atherosclerosis, 27, 383 (1977). The existence of Milk Factor and it's action in reducing blood cholesterol levels is mammals is now well established, having been confirmed by several other investigators. These literature reports include: Howard, A. N. and J. Marks, Lancet, 2, 255 (1977); Malinow, M. R. and P. McLaughlin, Experientia, 31, 1012 (1975); Kritchevsky, D., S. A. Tepper et al, American Journal Clinical Nutrition, 31, 518 (1978); and Hepner, G., R. Fried et al, American Journal Clinical Nutrition, 32, 19 (1979).
The research on which the present application is based has been partially published: Mann, G. V., Milk Factor--A Regulator of Cholesteremia, Abstract American Society of Clinical Nutrition, (May 3, 1979); and Mann, G. V., Ein Regulator den Cholesteramie, Bulletin European Organization for Control of Circulatory Disease, (Bonn, Nov. 9, 1979). As reported in the cited abstract, Dr. George V. Mann discovered a variety of Pseudomonas fluorescens which when propagated in milk was capable of producing from a 25 to 50 fold increase in the Milk Factor content of the milk. This microorganism is also referred to with respect to its MF-producing capacity in the cited Bulletin, although not further identified therein. Milk Factor itself was described as a small, non-protein, acidic, volatile molecule, which had not yet been molecularly characterized. The new strain or sub-species of P. fluorescens discovered by Dr. Mann has not been publicly available, and has been maintained under the control of Dr. Mann in his laboratory at Vanderbilt University School of Medicine, Department of Biochemistry, Nashville, Tenn. In connection with the filing of the prior application, Ser. No. 209,835, this strain or sub-species was deposited on a restricted basis with the American Type Culture Collection, Rockville, Md., and has been assigned the name Pseudomonas fluorescens loitokitok (ATCC No. 31732).